首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
A framework for the protection of the general public has been in existence for a very long time, although steps have recently been made by the ICRP to ensure that it is more fully comprehensive with regard to all actual and potential exposure situations. Protection of the environment, however, has only recently begun to be addressed in a structured manner, and is still an evolving subject. Nevertheless, it needs to be centred around some form of parallel framework to that which has evolved for the protection of human beings, although clearly on a different scale. It also needs to be embedded within the basic science of radiobiology, and form a central part of radioecology.  相似文献   

2.
Formaldehyde, an economically important chemical, is classified as a human carcinogen that causes nasopharyngeal cancer and probably leukemia. As China is the largest producer and consumer of formaldehyde in the world, the Chinese population is potentially at increased risk for cancer and other associated health effects. In this paper we review formaldehyde production, consumption, exposure, and health effects in China. We collected and analyzed over 200 Chinese and English documents from scientific journals, selected newspapers, government publications, and websites pertaining to formaldehyde and its subsequent health effects.Over the last 20 years, China's formaldehyde industry has experienced unprecedented growth, and now produces and consumes one-third of the world's formaldehyde. More than 65% of the Chinese formaldehyde output is used to produce resins mainly found in wood products — the major source of indoor pollution in China. Although the Chinese government has issued a series of standards to regulate formaldehyde exposure, concentrations in homes, office buildings, workshops, public places, and food often exceed the national standards. In addition, there have been numerous reports of formaldehyde-induced health problems, including poisoning and cancer. The lack of quality epidemiological studies and basic data on exposed populations emphasizes the need for more extensive studies on formaldehyde and its related health effects in China.  相似文献   

3.
This paper examines the impact of foreign penetration on the public firm in a mixed oligopolistic market. Through the establishment of a mixed double oligopoly market, this paper analyzes how the share of foreign investment affects the environmental policy, the pollutant emission, and the social welfare under the condition of the state tax. The results show that: first, the introduction of foreign investment has some crowding-out effects on the social level of output. Second, the entry of foreign investment increases the profit of the public firm by a large margin, and the maximum profit of the private firm has been reduced. Third, the increase of foreign investment in public firm does not necessarily improve the environment.  相似文献   

4.
近20余a来,互花米草在我国沿海及河口滩涂快速扩散,已成为我国海岸盐沼中最重要的入侵植物。上海崇明东滩是我国长江口的国际重要湿地,目前受到了互花米草入侵的严重威胁。自1995年在崇明东滩首次发现互花米草以来,互花米草的分布面积已超过1 600 hm2。总结了近几年在崇明东滩进行的互花米草相关研究,旨在对互花米草的控制与管理提供科学依据。目前互花米草主要分布在崇明东滩的东部及北部,决定其入侵动态与分布的主要因素在于:(1)互花米草对沿海滩涂环境具有良好适应与耐受能力;(2)人为引种大大加快了互花米草的扩张速度;(3)崇明东滩湿地的水分盐度条件特征导致互花米草主要分布在崇明东滩的东部与北部。根据互花米草的生理学特征和长江口地区的水文特点可以推断:互花米草在东滩东部和北部将继续扩张,但目前尚难入侵东滩南部区域,而人类活动可能加剧互花米草入侵。根据互花米草的入侵现状和趋势,必须尽快采取多种途径对互花米草进行控制和管理  相似文献   

5.
This paper reviews the current knowledge on the toxicity, speciation and biogeochemistry of arsenic in aquatic environmental systems. The toxicity of arsenic is highly dependent on the chemical speciation. The effects of pH, Eh, adsorbing surfaces, biological mediation, organic matter, and key inorganic substances such as sulfide and phosphate combine in a complex and interwoven dynamic fashion to produce unique assemblages of arsenic species. The number of different arsenic species found in environmental samples and an understanding of the transformations between arsenic species has increased over the past few decades as a result of new and refined analytical methods. Changes in arsenic speciation and in total arsenic content of foods upon processing have suggested possible risks associated with processed and unprocessed food. Arsenic removal from water using adsorbents, chemical oxidation, photolysis and photocatalytic oxidation techniques is also reviewed.  相似文献   

6.
As in many other developing countries, cities in Bangladesh have witnessed rapid urbanization, resulting in increasing amounts of land being taken over and therefore land cover changing at a faster rate. Until now, however, few efforts have been made to document the impact of land use and land cover changes on the climate, environment, and ecosystem of the country because of a lack of geospatial data and time-series information. By using open source Landsat data integrated with GIS technologies and other ancillary data, this study attempts to classify land use and create land cover maps, enabling post-classification change detection analysis. By this method, we document the spatial and temporal trajectory of urban expansion in Chittagong, the second largest city in Bangladesh, over a 36-year period. The findings suggest that, over the study period, 56 % of the land cover has undergone change, mainly because of the expansion of built-up areas and other human activities. During the 36-year period, the built-up area around Chittagong city has expanded by 618 %, with an average annual rate of increase of 17.5 %. As a result of rapid urbanization, the vegetated hills near urban development areas face serious threats of further encroachment and degradation, given that 2178 ha of hills have already been intruded over the study period. Because urbanization processes in Bangladesh have traditionally been viewed as the result of population growth and economic development, very little work has been done to track the potential growth trajectory in a physical or spatial context. This study, therefore, will contribute to the current understanding of urban development in Bangladesh from a temporal and spatial point of view. Findings will be able to assist planners, stakeholders, and policy makers in appreciating the dynamism of urban growth and therefore will facilitate better planning for the future to minimize environmental impacts.  相似文献   

7.
西藏第二产业发展现状分析   总被引:1,自引:0,他引:1  
西藏解放以来,第二产业从无到有经历了曲折的发展历程,发展迅速,总产值比重不断提高,已形成以矿产资源开采加工为主的较为完备的产业体系.但无论与全国平均水平还是西部欠发达地区相比,西藏第二产业发展仍相对落后,表现在产值比重低、产业发展对地方经济拉动能力非常有限,产业链短,效率低,产业结构偏离度高,难以有效吸收当地劳动力就业等方面.同时企业规模偏小,工业集中化低,没有形成有效的产业集聚地.优先发展第二产业,产业结构调整,就业人口向第二产业转移仍是未来西藏产业结构调整的重要任务.本文重点分析西藏第二产业产值、结构和劳动生产率、种类和规模变化,探讨了西藏第二产韭发展现状,认为当前西藏第二产业发展中存在较大问题,主要表现在重工业比重大,民用工业发展滞后,工业可持续性不强等,基于上述问题,文章提出了加大投资力度、加强人才培养、优化产业结构、积极发展民营企业和提高工业集中度的对策建议.  相似文献   

8.
通过构建“劳动力转移-性别差异-农地流转及合约选择”分析框架,分析劳动力转移性别差异背后的行为经济学含义,进而探讨不同性别的劳动力转移对农户农地流转供给决策与合约选择的差异化影响机制。理论研究表明,女性在家庭中起粘结家庭成员的作用,女性劳动力非农就业更能体现家庭的“离农”,因而女性劳动力的非农就业行为对农户农地流转供给决策具有更明显的促进作用;男性是农户家庭在村庄中排他能力的标志,具有不可忽视的农地流转风险规避功能,因而男性劳动力的外出就业距离对农户农地流转的合约选择起决定性作用。利用全国9省(区)4772个农户样本数据进行实证分析,计量结果表明:①女性劳动力非农就业比例每增加10%,农户转出农地面积占承包地面积比例增加1.06%;②男性劳动力县外就业比例每增加10%,农户转出农地时签订关系型合约的可能性增加1.11%;③男性劳动力县外就业比例每增加10%,意愿合约形式为无合同的可能性增加0.63%,意愿合约形式为口头合同的可能性增加0.29%,意愿合约形式为书面合同的可能性减少0.91%。这意味着,为了劳动力流转市场与农地流转市场更流畅地互动,应为农村女性劳动力营造一个更加合适、有利和公平的非农就业环境,这可成为未来农村劳动力就业扶持政策的重要方向。另一方面,促进正式契约与关系型合约的有机衔接,有利于农地流转合约的正式化与规范化,从而为农地流转市场的健康发育提供有力保障。  相似文献   

9.
How to choose among the dozen policy instruments available to environmental management agencies has been a matter of concern and debate among environmental economists for the entire life of the profession – nearly four decades. The ability, or lack of it, to measure the quantities or observe the actions made "enforceable" by particular policy instruments ought clearly to be central to this choice. However, all too often the monitoring problem has been assumed away. When it is reintroduced in realistic forms, we find, not surprisingly, that some favorite policy instruments, such as pollution charges, are not applicable to some important problems, such as runoff pollution from farms; that marginal subsidies, by changing the burden of proof, may no longer be symmetric with charges; and that the apparent freedom from monitoring requirements of the newly fashionable instrument involving the public provision of information about firms or products is "paid for" by our inability to say anything about its performance on other dimensions that are also of interest. Electronic Publication  相似文献   

10.
Research aimed at understanding the response of plants to ozone has been conducted for over four decades but little of it has addressed intact natural systems. Even so, there is sufficient scientific information at this time to support air quality standards that will protect natural terrestrial ecosystems from ozone. What is unknown is the risk associated with continued exposure of natural systems, including both above- and below-ground components, in combination with other stresses including changing temperature and precipitation, elevated carbon dioxide, pests and pathogens, invasive species, and other activities that may fragment the landscape. Research to support an assessment of the ecological risk associated with ozone as it exists, in a milieu of stresses, must include endpoints beyond those addressed in the past, primarily productivity and species composition. To estimate the risk to society of ozone impacts on natural systems, endpoints such as the integrity of soil food webs, the quantity and quality of water supplied from terrestrial ecosystems, wildlife and recreational values, and the transfer and fate of carbon, nutrients, and water within the systems must be quantified. Not only will this research provide the basis for a sound estimate of risk, but also it will improve our understanding of fundamental ecosystem processes.  相似文献   

11.
As the global population is expected to reach 9 billion by 2050, humanity needs to balance an ever increasing demand for food, energy and natural resources, with sustainable management of ecosystems and the vital services that they provide. The intensification of agriculture, including the use of fertilisers from finite sources, has resulted in extensive soil degradation, which has increased food production costs and CO2 emissions, threatening food security. The Bioenergy sector has significant potential to contribute to the formation of a circular economy. This paper presents the scientific, regulatory and socioeconomic barriers to the use of the nutrient waste streams from biomass thermal conversion (ash) and anaerobic digestion (digestate) as sustainable soil amendments for use in place of traditional fertilisers. It is argued that whilst the ability of combined ash and digestate to remedy many threats to ecosystems and provide a market to incentivise the renewable bio-energy schemes is promising, a step-change is required to alter perceptions of ‘waste’, from an expensive problem, to a product with environmental and economic value. This can only be achieved by well-informed interactions between scientists, regulators and end users, to improve the spread and speed of innovation with this sector.  相似文献   

12.
Freshwater mussels, Velesunio angasi, along Magela Creek in Australia’s Northern Territory were examined to study radionuclide activities in mussel flesh and to investigate whether the Ranger Uranium mine is contributing to the radium loads in mussels downstream of the mine. Radium loads in mussels of the same age were highest in Bowerbird Billabong, located 20 km upstream of the mine site. Variations in the ratio of [Ra]:[Ca] in filtered water at the sampling sites accounted for the variations found in mussel radium loads with natural increases in calcium (Ca) in surface waters in a downstream gradient along the Magela Creek catchment gradually reducing radium uptake in mussels. At Mudginberri Billabong, 12 km downstream of the mine, concentration factors for radium have not significantly changed over the past 25 years since the mine commenced operations and this, coupled with a gradual decrease of the 228Ra/226Ra activity ratios observed along the catchment, indicates that the 226Ra accumulated in mussels is of natural rather than mine origin. The 228Th/228Ra ratio has been used to model radium uptake and a radium biological half-life in mussels of approximately 13 years has been determined. The long biological half-life and the low Ca concentrations in the water account for the high radium concentration factor of 30,000-60,000 measured in mussels from the Magela Creek catchment.  相似文献   

13.
In the Segara Anakan lagoon, Java, 21 tree species and 5 understorey genera have been identified. Average tree density is 0.80 ± 0.99 Ind./m2 with 48.71% seedlings and an average basal area of 9.86 ± 10.54 cm2/m2. Tree density and diversity are high in the eastern part of the lagoon, located near the city of Cilacap. There, the dominant tree species are Aegiceras corniculatum, Nypa fruticans and Rhizophora apiculata, of which the two latter are characteristic for mature forests. By contrast, understorey species and the pioneer species (Avicennia alba, Aegiceras corniculatum and Sonneratia caseolaris) dominate the central lagoon where several rivers discharge. Compared to former studies, seedling density and tree diameter in the central lagoon has declined considerably and tree species dominance has changed. The high sedimentation rates and deforestation are likely to prevent the formation of a mature forest there. Tree communities are more equilibrated in the eastern lagoon which points to a more stable and less disturbed mangrove forest.  相似文献   

14.

The relationship between stability and change in social-ecological systems has received considerable attention in recent years, including the expectation that significant environmental changes will drive observable consequences for individuals, communities, and populations. Migration, as one example of response to adverse economic or environmental changes, has been observed in many places, including parts of the Far North. In Arctic Alaska, a relative lack of demographic or migratory response to rapid environmental and other changes has been observed. To understand why Arctic Alaska appears different, we draw on the literature on environmentally driven migration, focusing on three mechanisms that could account for the lack of response: attachment, the desire to remain in place, or the inability to relocate successfully; alternatives, ways to achieve similar outcomes through different means; and buffering, the reliance on subsidies or use of reserves to delay impacts. Each explanation has different implications for research and policy, indicating a need to further explore the relative contribution that each makes to a given situation in order to develop more effective responses locally and regionally. Given that the Arctic is on the front lines of climate change, these explanations are likely relevant to the ways changes play out in other parts of the world. Our review also underscores the importance of further attention to the details of social dynamics in climate change impacts and responses.

  相似文献   

15.
This article provides a short overview of the main themes of ecological economics (EE). It is argued that EE provides a platform that fosters multidisciplinary environmental research by bringing together the core contributing disciplines – economics and ecology. In addition, EE is regarded as a pluralistic approach to environmental research that can be set opposite to, and has indeed developed as a response to, traditional environmental and resource economics. A comparison of the two fields is presented to clarify the essential differences between them. In addition, specific themes are examined in more detail. These include: sustainable development; the growth debate; international trade; dynamic processes; and behaviour and policy. Electronic Publication  相似文献   

16.
The measurement, reporting, and verification (MRV) of climate finance was originated from discussions under the United Nations Framework Convention on Climate Change (UNFCCC). It has been one of the key issues of global climate negotiations since 2009 and will continue to be of significant importance in addressing climate change and strengthening international trust. This paper analyses the concept, the objective, and the progress of the MRV of climate finance based on reviews of the latest literature and think-tank reports regarding climate finance regime and MRV. Following the analysis, challenges faced with the MRV of climate finance are illustrated. This paper presents that the comparability of climate finance data needs to be improved due to the variety of methodologies used for disaggregating climate finance. In addition, the integrality of the MRV system of climate finance has been impaired by the lack of feedback mechanism from the recipients to the contributors in reporting system. Furthermore, although accounting system of climate finance has been developing and improving, it remains incapacity in providing accurate data on disbursed climate finance. Responding to the above challenges, this paper proposes the key tasks in establishing a comprehensive MRV system for climate finance at international level. The tasks involve developing a measurement system with consistent data basis and accounting basis, a reporting system with more detailed guidance and standardized formats, as well as a verification mechanism balancing top-down and bottom-up review processes. In the last section, this paper concludes that the establishment of an improved MRV of climate finance requires concerted cooperation and negotiations between developed and developing country Parties under the UNFCCC. As one of the few developing country donors to the Global Environmental Facility (GEF), China is suggested to clarify its propositions as a developing country in aspects such as concept, coverage, and architecture of climate finance and MRV system, and gain bargaining power in improving operating and technical rules of international climate finance regime.  相似文献   

17.
Formulating the GSDR Formulating the GSDR (global sustainable development report) is one of the important achievements initiated by the “Rio +20” summit, and it has received worldwide attention. Nowadays, the international community has made a preliminary consensus on the orientation, key focuses, frameworks, and time schedule of GSDR. But, there are still great divergences in the relationship between GSDR and SDGs/post-MDGs (sustainable development goals/post-2015 development agenda), the GSDR organizational model, and whether countries writing their own national sustainable development report or not. After reviewing the whole process of formulating GSDR, some recommendations for writing GSDR from the Chinese perspective are proposed. The GSDR report should be a science-based and policy-making-oriented assessment report. The GSDR should focus on the priority areas that SDGs/post-MDGs have already identified as core fields. “Limited in number, easy to quantify, and universally applicable” comprehensive assessment indices of sustainable development should be proposed. A GSDR international working group of experts should be established. Countries should be encouraged to formulate the “National Sustainable Development Report” according to their own domestic practices. GSDR should be integrated with the high-level political forum (HLPF). Meanwhile, some suggestions on China’s participation in the GSDR process are also proposed. China’s 2030 mid-term and long-term national sustainable development goals (CSDGs) based on both the SDGs/post-MDGs and domestic practice are proposed. According to the implementation of national sustainable development goals, China should start the appropriate assessment of the progress and regularly report on the national sustainable development. Chinese scientists should be encouraged to actively participate in the process of GSDR.  相似文献   

18.
Environment, Development and Sustainability - Ecotourism development is a strategy of the Philippine Government. The existence of untapped natural resources and cultural/heritage assets has impeded...  相似文献   

19.
At present, main objective of Chinese government is building a harmonious society, which needs great efforts to promote harmonious development between people and nature as well as people and people. Implementing eco-compensation has been proven effective for achieving the objective. In fact, Chinese government has begun groping for establishing eco-compensation system since the beginning of 1980's and has obtained some experiences until now. However, eco-compensation system in China is still unperfected and has not played an important role for building a harmonious society and promoting sustainable development in today's China. An integrated and effective methodology system is still not formed, and there are still many problems need to be resolved. Based on these problems and experiences from China and other countries, this study attempts to give some suggestions for perfecting eco-compensation system of Chinese government.  相似文献   

20.
The Pechelbronn oilfield (Rhine Graben, France), where mining activity ended in the 1960s, has been used for waste disposal for twenty years. Since the wastes are varied, work is underway to identify the discharged materials and their derivatives, as well as to locate and quantify potential discharge sites. Two major goals were assigned to the present work. The first was to identify or refine the location of hidden structures that could facilitate gas emanation up to the surface, by studying soil gas concentrations (mainly 222Rn, CO2, CH4 and helium) and carbon isotope ratios in the CO2 phase. The second was devoted to examining, from a health and safety viewpoint, if the use of the oilfield as a waste disposal site might have led to enhanced or modified gas emanation throughout the area.It appeared that CO2 and 222Rn evolution in the whole area were similar, except near some of the faults and fractures that are known through surface mapping and underground observations. These 222Rn and CO2 anomalies made it possible to highlight more emissive zones that are either related to main faults or to secondary fractures acting as migration pathways. In that sense, the CO2 phase can be used to evaluate 222Rn activities distant from tectonic structures but can lead to erroneous evaluations near to gas migration pathways. Dumping of wastes, as well as oil residues, did not appear to have a strong influence on soil gaseous species and emanation. Similarly, enhanced gas migration due to underground galleries and exploitation wells has not been established. Carbon isotope ratios suggested a balance of biological phenomena, despite the high CO2 contents reached. Other monitored gaseous species (N2, Ar, H2 and alkanes), when detected, always showed amounts close to those found subsurface and/or in atmospheric gases.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号